package org.hnsd.train.pattern.observer;

import java.util.Vector;

/**
 * @author youqd
 * @tag.date 2023-11-07 22:55
 **/
public abstract class Subject {
    public Vector<Observer> obsVector = new Vector<Observer>();
    public abstract void attach(Observer observer);
    public abstract void detach(Observer observer);
    public abstract void notifyObserver();
}
